Explanation: When Mary comes out of the room and saw something in red color, it shows she does acquired some new fact of knowledge. The knowledge deals with the qualitative features of their experiences.
They should undergo few experiment to verify their hypothesis. As their hypothesis is based on the color, their experiment will be something related color matching.
And when Marry was inside the room, she missed some knowledge. She lacked about other people's experiences. They should look for evidence that will justify their conclusion.